Earthy and nutty Gruyère cheese puts a new spin on this no-bake green bean casserole that frees up precious oven space.
2 (16 oz) pkgs frozen French-cut green beans
6 tbsp unsalted butter, divided
1/4 cup all-purpose flour
2 cups whole milk
1/2 lb Gruyère cheese, coarsely shredded
1/4 cup panko bread crumbs
2 tbsp chopped chives
Heat the green beans according to package directions.
Meanwhile, in a 12-inch skillet, melt 4 tbsp butter on medium. Whisk in the flour and cook, whisking constantly, for 2 min., until flour has darkened slightly in color and mixture is smooth. Slowly add the milk, whisking constantly to smooth out any lumps. Heat until sauce comes to a simmer and thickens slightly.
Remove from heat and stir in the Gruyère by handfuls until smooth. Season with salt and pepper to taste. Stir in green beans, then transfer to a 2-qt baking dish.
In a 10-inch nonstick skillet, melt remaining 2 tbsp butter on medium-low. Stir in the bread crumbs and cook 2–3 min., until golden brown, stirring often. Season with salt and pepper to taste. Remove from heat and stir in the chives. To serve, sprinkle crumbs over green beans.